Commutator with oil slinger



April 14, 1964 J. P. CLARK 3, 9,

COMMUTATOR WITH OIL SLINGER Filed Oct. 25, 1961 44 Fig, I

' INVENTOR.

Joseph F. Clark His Attorney United States Patent 3,129,350 CGMMUTATORWITH OIL SLINGER Ioseph P. Clark, Rochester, N.Y., assignor to GeneralMotors Corporation, Detroit, Mich, a corporation of Delaware Filed Get.25, 1961, Ser. No. 147,642 7 Claims. (Cl. 310235) This inventionpertains to commutators, and particularly to an improved commutatorconstruction for dynamoelectric machines.

Heretofore, it has been customary in commutator-type dynamoelectricmachines to attach a flared metal ring to the armature shaft between thecommutator and the support for the armature shaft, this ring coactingwith the bearing to prevent the flow of lubricant onto the commutatorsegments during rotation of the armature. This ring has been known inthe art as an oil slinger, a typical example of a dynamoelectric machineembodying such an oil slinger being shown in Simmons et a1. Patent2,982,873. The present invention relates to the formation of an integraloutwardly flared rim on the core of the commutator which functions as anoil slinger and thus eliminates the necessity for the separate ringwhich was formerly press fitted onto the armature shaft.

Accordingly, among my objects are the provision of a commutatorconstruction embodying integral oil slinger means; and the furtherprovision of a commutator core having an integral outwardly flared rimon the bearing end thereof constituting an oil slinger.

The aforementioned and other objects are accomplished in the presentinvention by forming an integral axially extending rim on the bearingend of the commutator core having an outer diameter less than thediameter of the commutator shell and having an outwardly flared innersurface. Specifically, the improved commutator construction includes aninner cylindrical commutator shell of conductive metal which forms apart of the retaining wall of the mold cavity and is mechanicallyinterlocked by suitable anchor means with the insulative core body ofthe commutator. The core body is formed with an. integral frusto conicalportion on the armature end thereof, and has a stepped diameter throughbore. The larger diameter portion of the through bore is encompassed bythe frusto conical insulating portion, and the smaller diameter throughbore is surrounded by the commutator shell. In order to facilitate pressfitting of the commutator onto a knurled armature shaft, in accordancewith the teachings of copending application Serial No. 774,295, filedNovember 17, 1958, in the name of Carlson et al. and assigned to theassignee of this invention, now Patent No. 3,080,615, the smallerdiameter through bore is fluted by forming three ribs circumferentiallyspaced by three recesses. The bearing end of the core body is formedwith an integral axially extending annulus having an outwardly flaredinner wall so as to form an oil slinger which coacts with the bearingsupport for the commutator end of the armature shaft to prevent the flowof lubricant from the bearing onto the commutator segments.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred embodiment of the present invention isclearly shown.

In the drawing:

FIGURE 1 is a plan view of the improved commutator construction.

FIGURE 2 is an end view of the commutator shown in FIGURE 1, taken inthe direction of arrow 2.

FIGURE 3 is a sectional view of the commutator taken along line 3-4: ofFIGURE 2.

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FIGURE 4 is an enlarged sectional view taken along line 44 of FIGURE 3.

FIGURE 5 is an enlarged fragmentary view taken along line 5-5 of FIGURE2.

FIGURE 6 is an enlarged fragmentary sectional view showing thecommutator press fitted onto an armature shaft and the relationshipbetween the integral oil slinger and the bearing support for thecommutator end of the armature shaft.

With particular reference to FIGURES 1 and 3, the improved commutatorconstruction includes a core 10 composed of suitable insulating materialsuch as phenolic, a condensation product of thermosetting resin, and askeleton cylindrical commutator shell 40 of conductive metal havinghook-type anchor means 42 imbedded in the core 10. Subsequent to curingthe core body 10, the commutator shell 40 has a plurality of slots cuttherein to form commutator segments 44 as seen in FIGURE 1.

The core body 10 has a stepped diameter through bore including a largerdiameter portion 12, the major portion of which is within a frustoconical insulating portion 14 that extends axially outward from thecommutator shell 40. The portion of the bore within the core 10 which issurrounded by the commutator shell 40 is fluted by the formation ofthree inwardly extending ribs 16, the ribs 16 being circumferentiallyspaced, and each subtending an angle of substantially 60. The nominaldiameter of the opening formed by the ribs 16 is less than the diameterof the bore 12. The ribs 16 are spaced apart by recesses 18 whichlikewise subtend an angle of substantially 60, the nominal diameter ofthe recesses likewise being less than the diameter of the bore 12.

The core body 10 also includes an integral axially extending rim, orannulus, 25 having an outer diameter less thna the diameter of thecommutator shell 40. The rim 2% has an outwardly flared inner wall 22 asclearly seen in FIGURES 3 and 5, and the edge 24 thereof is axiallyspaced from the commutator shell.

Referring to FIGURE 6, when the improved commutator is press fitted ontoan armature shaft 46, the armature is mounted in a motor frame 48 havinga self-aligning bearing 5t) at the commutator end thereof, the bearingbeing retained in assembled relation with the frame by a retainer 52carried by a slinger shield 54. As is customary, a lubricant impregnatedfelt packing 56 is interposed between the bearing retainer 52 and theframe 48, and the integral oil slinger rim 20 of the commutator extendsinto the opening in the slinger shield 54 and coacts therewith toprevent the flow of lubricant from the bearing 50 onto the commutatorsegments 44.

By following the teachings of the present invention it is readilyapparent that economies can be realized in the manufacture ofdynamoelectric machines by the formation of an integral slinger ring onthe commutator core in that the separate slinger rings heretofore usedcan be eliminated, and also the assembly operation associated therewithcan be eliminated. In addition, by forming the core body with a flutedbore more realistic production tolerances can be used in the pressfitting operation with out fracturing the core body.

While the embodiment of the invention as herein disclosed constitutes apreferred form, it is to be understood that other forms might beadopted.

What is claimed is as follows:

1. A commutator comprising, a core of synthetic resinous material,segments on at least a portion of the exterior of said core, and anaxially extending rim integral with said core having its edge spacedaxially from said segments and constituting an integral oil slinger forsaid commutator.

2. A commutator comprising, a core of synthetic resinous material,segments on at least a portion of the exterior of said core, and anaxially extending rim integral with said core and of smaller diameterthan the diameter of said segments and having an edge spaced axiallyfrom said segments so as to constitute an oil slinger for saidcommutator.

3. A commutator comprising, a core of synthetic resinous material,segments on at least a portion of the exterior of said core, and anaxially extending rim integral with said core having an outwardly flaredinner surface and an edge spaced axially from said segments so as toconstitute an oil slinger for said commutator.

4. A commutator comprising, a core of hardened thermosetting plasticmaterial, a plurality of circumferentially spaced commutator segments onat least a portion of the exterior of said core and interlockedtherewith, and an oil slinger formation extending axially outward fromand integral with said core.

5. A commutator comprising, a core of hardened thermosetting plasticmaterial, a plurality of commutator segments on at least a portion ofthe exterior of said core and interlocked therewith, and an oil slingerformation extending axially outward from and integral with said core andhaving a diameter less than the diameter of said commutator segments. a

6. In a commutator type dynamoeleetric machine having a frame, anarmature shaft journalled therein and a commutator including a coreattached to said armature shaft, the improvement which comprises an oilslinger formation on said commutator and integral with said core.

7. In a commutator type dynamoelectric machine having a frame, a bearingcarried by said frame and an armature shaft journalled in said bearingand having a commutator including a core, the improvement whichcomprises oil slinger means on said commutator and j integral with saidcore for and coacting with said bearing to prevent the flow of lubricantfrom said bearing onto said commutator.

References Cited in the file of this patent UNITED STATES PATENTS1,014,628 Lieber Jan. 9, 1912 1,993,966 Kessler Mar. 12, 1935 FOREIGNPATENTS 470,944 Great Britain Aug. 25, 1937

1. A COMMUTATOR COMPRISING, A CORE OF SYNTHETIC RESINOUS MATERIAL,SEGMENTS ON AT LEAST A PORTION OF THE EXTERIOR OF SAID CORE, AND ANAXIALLY EXTENDING RIM INTEGRAL WITH SAID CORE HAVING ITS EDGE SPACEAXIALLY FROM SAID SEGMENTS AND CONSTITUTING AN INTEGRAL OIL SLINGER FORSAID COMMUTATOR.